In this work, we develop a linear robust minimum mean-square error (RMMSE) precoder to mitigate the effects of imperfect channel state information (CSI) and the intra-cluster (ICL) and out-of-cluster (OCL) interference in cell-free (CF) multiple-antenna systems. The proposed precoder includes statistical information of the OCL interference in its derivation, allowing a more effective interference mitigation. An analysis of the sum-rate that can be obtained by the CF system is carried out and an expression quantifying the theoretical gains of mitigating OCL interference are derived. Simulation results corroborate that the proposed RMMSE precoder effectively mitigates ICL and OCL interference.

翻译：本文提出了一种线性鲁棒最小均方误差（RMMSE）预编码器，用于抑制无蜂窝（CF）多天线系统中不完美信道状态信息（CSI）以及集群内（ICL）和集群外（OCL）干扰的影响。所提出的预编码器在其推导过程中包含了OCL干扰的统计信息，从而能够实现更有效的干扰抑制。对CF系统可达的和速率进行了分析，并推导出量化抑制OCL干扰理论增益的表达式。仿真结果证实，所提出的RMMSE预编码器能有效抑制ICL和OCL干扰。